(a) Field of the Invention
The present invention relates to a codeword retransmitting/decoding method and transmitting/receiving apparatus using feedback information. More particularly, the present invention relates to a codeword retransmitting/decoding method and transmitting/receiving apparatus for requesting data retransmission and correcting an error using feedback information when data are erroneously transmitted.
(b) Description of the Related Art
In a cellular communication system, zones are divided into a plurality of cells. Each cell includes at least one or more base stations.
In each cell, a base station communicates with a plurality of mobile terminals, and connects a base station-included wireless network to each mobile terminal.
Communication between the base station and a terminal is achieved by dividing a great deal of data through traffic packets.
For such communication between the base station and the terminal, the packet data must be recoverable when a data error occurs on a wireless link.
A technology for correcting such a digital data transmission error may include an error correcting code.
The error correcting code is configured by adding a residue of bits according to error correction rules to an original code when the original code has the error at the bits thereof.
The error correcting code includes a low density parity check (LDPC) code and a turbo code. The LDPC code is a code in which the number of other numbers excluding 0 is smaller in comparison with a length of the code in a parity check matrix. The turbo code is a code which is generated using a combination of two or more convolution codes.
When there is an error in information bits included in a new code transmitted through the error correcting code, a transmission node or receiving node requests an additional resource to the packet data and transmits additional information for the respective information.
Accordingly, it is determined whether the additional information is needed and requested. Such additional information transmission is referred to as an automatic repeat request (ARQ).
The ARQ is for the transmission node or receiving node to detect a data error generated in a communication channel, and to request data retransmission and to correct the data error when the packet data include an error.
The transmission node (base station or terminal) sequentially transmits buffered packet data to the receiving node (terminal or base station) when using a radio resource. When the receiving node determines that there is lost packet data in the received packet data, the receiving node generates a data retransmission request massage of the loss packet data and transmits the same to the transmission node.
When the transmission node receives the data retransmission request message from the receiving node, it retransmits a part of the lost packet data and the related data thereto to the receiving node.
Generally, in a communication system, the data retransmission process may improve a success possibility of the data transmission. However, since the same information is transmitted many times, the resources may be relatively wasted.
In addition, the transmission node grossly transmits all lost packet data and the data related thereto. Meanwhile, the lost packet data may often have an error at some bits thereof.
Accordingly, the one-stop transmissions of the packet data have a problem in use of a radio resource.
The communication system needs an improved ARQ for requesting a minimum of additional resources so as to effectively use a bandwidth and for transmitting additional information so as to effectively use a resource.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.